Alternative Port EFI IntakesThis board is for tech discussions and questions about aftermarket port EFI such as the HSR, MR, SR, BBK, FIRST, etc.
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Well just talked to comp cams and this is what they recomended
COMPETITION CAMS PART NUMBER: 08-502-8
ENGINE: CS XR269HR-12
GRIND #: CS XR269HR-12
INT EXH
VALVE ADJUSTMENT HYD HYD
GROSS VALVE LIFT: .495 .503
DURATION AT
.006 TAPPET LIFT 269 276
VALVE TIMING OPEN CLOSE
AT .006 INT 26 62
EXH 74 22
THESE SPECS ARE FOR CAM INSTALLED
@ 108.0 INT C/L
INT EXH
I think the HOT cam would be a great choice. I would've gone with it, but I wanted to get a little more modern/aggressive with the ramps so I chose a comp cam VERY similar to the one they quoted you. Have you checked the boards here for a used HOT cam?
The cam I used is:
PN 08-422-8
XR270-HR
It looks like the same cam as above but on a 110 instead of 112. Ran great in my car, and I've since gone with different heads and a solid roller cam so I'd sell it cheap if you're interested.
Comp cams has a software that you can use to choose a cam and it will estimate the horsepower and torque curves for your engine configuration.
They don't have a ram jet manifold but you can choose the TPIS miniram, which is pretty close.
The horsepower differences between the mild hydraulic rollers and the xfi cams was barely 15 to 25, or 375 to 400 peak values. The xfi cams would require upgraded springs etc.
I decided to use the zz4 cam for my ram jet setup. The duration matches the rpm range for a street engine and the lift would take advantage of flow of the vortec style heads.
I am actually planning to buy the etec 170s since the SDPC heads are the only other heads that can handle the lift. There is a ram jet bin file for the 730 ecm on Moates.net that I plan to use as a starting point. I am also planning to build a custom egr setup, to make sure I pass ohio emissions.
I like the zz9 cam specs, but couldn't find it for a decent price. I bought the zz4 take-off on ebay for $89.
They don't have a ram jet manifold but you can choose the TPIS miniram, which is pretty close.
I've never seen any proof that the Ramjet flows close to what the miniram does; actually I don't know what the Ramjet flows. I think the program is called Camquest 6, which I did mess around with for a bit. It also lets you choose the LT1 and LT4 manifolds, so I chose one of those when I did it.
).
